Flat type balanced armature relay

ABSTRACT

A flat type balanced armature relay of a reduced height. Coil bobbin with exciting coil and yoke are placed in a pile on header plate of magnetic material and the yoke and header are coupled by a permanent magnet disposed at a side of the bobbin. Rockable armature having at both ends contact spring driving pins is contained axially in the bobbin. A frame member for fixing the pile and magnet to the header has an adjusting spring means for urging the driving pins to render the switching operation stable and disposed in a manner readily accessible from sideward for adjusting the urging pressure. By varying the pressure properly, the relay may be adapted to be of one-stable, two-stable or center-stable type.

United States Patent 1 Mori et al.

[111 3,748,607 1 July 24, 1973 FLAT TYPE BALANCED ARMATURE RELAY [22] Filed: Aug. 25, 1972 [21] Appl. No.: 283,732

[30] Foreign Application Priority Data Sept. 30,1971 Japan 46/76734 [56] References Cited UNITED STATES PATENTS 3,258,556 6/1966 Juptner et al 335/125 3,307,127 2/l967 Leo 335/l28 3,368,170 2/l968 Sauer 335/86 3,705,368 l2/l972 Williams 335/203 Primary Examiner-"Harold Broome AttarneyWolfe, Hubbard, Leydig, Voit & Osann [57] ABSTRACT A flat type balanced armature relay of a reduced height. Coil bobbin with exciting coil and yoke are placed in a pile on header plate of magnetic material and the yoke and header are coupled by a permanent magnet disposed at a side of the bobbin. Rockable armature having at both ends contact spring driving pins is contained axially in the bobbin. A frame member for fixing the pile and magnet to the header has an adjusting spring means for urging the driving pins to render the switching operation stable and disposed in a manner readily accessible from sideward for adjusting the urging pressure. By varying the pressure properly, the relay may be adapted to be of one-stable, two-stable or center-stable type.

7 Claims, 9 Drawing Figures PATENTED Jul24|975 SHEU 2 0f 4 FLAT TYPE BALANCED ARMATURE RELAY This invention relates to balanced armature relays.

For a balanced armature relay of this kind, there has been already suggested, for example, a German Patent No. 1,213,917. The relay disclosed in this German patent is of a structure wherein an assembly held by two yokes from both sides of a coil containing an armature is fitted on a base plate having a lead terminal in the lower part,and has therefore a defect that the height of the relay is large. The present invention is to eliminate this effect that the height of the relay is large, by mounting a coil bobbin containing an armature on a header forming a part of a magnetic circuit, mounting a yoke on this coil bobbin and arranging a permanent magnet on the side of the coil bobbin and is further to obtain a relay making a stable operation by pressing a driving piece driving an operating spring setting a contact on or off by an adjusting spring.

A main object of the present invention is to provide a relay wherein the height is made small by placing a coil bobbin and yoke on a header.

Another object of the present invention is to provide the electromagnetic relay which can be made any type of one-stable, two-stable and center stable types by adjusting an adjusting spring.

The present invention shall be explained in the following with reference to the drawings in which:

FIG. I is a pershective view of an electromagnetic relay of the'present invention as disassembled;

FIGS. 2A, 2B and 2C shown an assembling order;

FIG. 3 is a perspective view of the present invention;

FIG. 4 is a partly sectioned elevation;

FIG. 5 is a side view;

FIG. 6 is an operation explaining view;

FIG. 7 shows other forms of a driving piece and glass balls.

An embodiment of the present invention shall be ex plained in the following.

FIG. 1 is a perspective view of a relay of the present invention as disassembled. l is a plate called a header, made of a magnetic material and having magnetic pieces 2 and 2' made of a magnetic material provided to project with a spacing between them in the middle of the plate. 3and 3' are lead terminals fixed to the header 1 through respective insulators 4 and arranged in parallel with each other. 5 is an armature made of a magnetic material nd provided with a pivoting hole 6 in the middle of the side. 7 is a Y-shaped driving piece made of iron and having insulating glass balls 8a and 8b fixed at the tips. 7', 8'a and 8'b are respectively the same. 9 is a shaft inserted into the hole 6. l0 and 10' are receiving plates made of an elastic material and having respectively holes 11 and 1] made in the middle.

Both ends of the shaft 9 are to be inserted respectively into said holes 11 and ll. 12 is a coil bobbin made of an insulator and having a coil 13 wound around it. 14 is a space provided in the coil bobbin 12. As described later, the armature 5 is contained in this space. 15 is a plate-shaped permanent magnet. 16 is a U-shaped yoke. 17a, 17b, 17a and 17'!) are L-shaped fixed contacts respectively welded to determined terminals in the lead terminal 3. l8 and 18' are operating springs fixed at the ends respectively to L-shaped supporting arms 19 and 19' which are welded in the lower parts respectively to determined ones of the lead terminals 3'. 20 is a fixing frame made of a nonmagnetic metallie material and having spring parts 21 and 21' for adjusting the spring system, fixing parts 22 and 22' for fixing the fixing frame 20 to the header 1 and bent parts 20' for holding a permanent magnet provided on both sides. 23 is a case made of a nonmagnetic metallic material. FIG. 7 shows another form of a driving piece to which a plurality of glass balls are fixed so as to beused in the case of setting a plurality of operating springs.

An assembly of a relay of the present invention shall be described in the following. FIGS. 2A, 2B and 2C show an assembling order.

FIG. 2A shows the header 1 in which the fixed contacts 17a, 17b, "'0 and l7'b are welded to the lead terminals 3. Then, the driving piece 7 is welded to one side of the armature 5 shown in FIG. 1, the shaft 9 is inserted into the hole 6 of the armature 5 and both ends of said shaft 9 are inserted into the holes 11 and l l of the receiving plate 10 and 10'. The armature in this state is inserted into the space 14 in the coil bobbin l2 and the driving piece 7' is welded to the other end of the armature 5. Then this coil bobbin 12 is fitted into the magnetic pole pieces 2 and 2 of the header 1. This state is shown in FIG. 2. Then, the supporting arms 19 and 19 of the operating springs 18 and 18' are welded to the lead terminals 3'.

Then, the permanent magnet 15 is set along the side the side opposite to the fix contacts 17a, 17b, l7'a and l7b of the coil bobbin 12, the yoke 16 is welded to the fixing frame 20 at least near the points at which the adjusting springs 21 and 21' of the fixing frame 20 are branched, is placed above the permanent magnet 15 and coil bobbin l2 and is pressed from above with the fixing frame 20 and the fixing parts 22 and 22' of the fixing frame 20 are welded to the upper surface of the header 1. This state is shown in FIG. 3. In such case, the adjusting spring parts 21 and 21 of the fixing frame 20 are respectively made to press the glass balls 8!) and 8'b above the driving pieces 7 and 7'.

Then the adjusting springs 21 and 21' are bent and adjusted to make any of one-stable, two-stable and center stable types.

After the assembling and adjustment, the assembly is vacuum-dried and then thecase 23 is welded to the header 1 in an inert gas atmosphere.

By the way, the width b of the permanent magnet 15 and the height a of the side 12' of the coil bobbin 12 are made substantially equeal to each other and the sides 16' of the yoke 16 are mounted on the side 12' of the coil bobbin l2.

The operation of the relay of the present invention shall be explained in the following.

Here, therev shall be explained the operation of an electromagnetic relay in which the adjusting spring is adjusted so that the electromagnet may be of a onestable type. 18 and 18' are operating springs whose free ends are respectively between the contacts 17a and between the contacts l7'a and "'12. In case the fixed contacts 17a and 17b are made normally closed contacts, if an electric current is flowed through the coil 13, the armature 5 will operate in response, the fixed contacts l7aand 17'!) will open and the fixed contacts 17b and will close in the structure.

0n the other hand, the relations between the spring forces of the contact springs 18 and 18' and the spring forces of the adjusting springs 21 and 21' and between the energizing attraction the force received by the armature when the coil is excited and the opening attraction the force received by the armature when the coil is not exited of the coil 13 are shown in FIG. 6. The moving distances travels of the driving pieces 7 and 7 are taken on the abscissa and the attractions and spring forces are taken on the ordinate. The point on the ordinate is a balancing point. In the diagram, the bent line a represents the spring characteristics of the operating spring, b represents the spring characteristics of the adjusting spring, 0 represents the spring characteristics of a combination of the operating spring and adjusting spring, d represents the energizing attraction and 2 represents the opening attraction.

As shown in the diagram, the position in which the combined spring force 0 which is a sum of the spring force a of the operating springs 18 and 18' and the spring force b of the adjusting springs 21 and 21 zero the position of the intersection with the abscissa is displaced leftward from the center 0 of the travel X of the driving piece and, at the same time, the combined spring force is so made as to be always between the energizing attraction d and opening attraction e. In the adjustment, the distance of the section in which one adjusting spring 21 is in contact with the head part of one glass ball 8'b is made n, the distance of the section in which the other adjusting spring 21 is in contact with the head part of the other glass ball 8b is made m, the rate of the distance in which the adjusting springs 21 and 21 are in contact respectively with the glass balls 8b and 8'b is varied under a condition that m is larger than n and at the same time the distance Q of the section in which the operating springs 18 and 18' are not in contact respectively with the glass balls 8a and 8b and 8'a and 8'b is varied to make a coordination.

As required, other auxiliary adjusting springs (not illustrated) may be provided beside the adjusting springs 21 and 21' so that a coordination may be made in response to the fluctuation of the attraction curve of the electromagnet.

The operation shall be described more particularly. In FIG. 3, when the side of the fixed contacts 17a and l7b which are normally closed contacts is closed and the glass ball 8b is in contact with the operating spring 18 this is the operation in the range of the A side in FIG. 6 if the coil 13 is excited, the glass ball 8'b will contact the operating spring 18' and the glass ball 8a will contact the operating spring 18 to open the side of the fixed contacts 17a and l7b and at the same time to close the side of the normally opened contacts 17b and l7'a this is the operation in range of the B side in FIG. 6 Then, if the exciting current passed through the coil 13 is cut off the glass ball 8'a will contact the contact spring 18' and the glass ball 8b will contact the operating spring 18 to close the side of the fixed contacts 17a and l8'b this is the operation in the range of the A side in FIG. 6 and to open the side of the fixed contacts 17b and l7a.

As described above, in the present invention, as the drivingpieces fixed to both ends of the balanced annature are made to be pressed with the adjusting springs, the spring forces can be easily adjusted from both side parts of the electromagnetic relay so that the efficiency of the electromagnet may be very high, the portion in which the combined spring force is zero may be displaced from the center of the driving piece travel and the combined spring force may be between the energizing attraction and opening attraction. Therefore, a balanced armature type polar relay making a one-stable operation is obtained. Thus, there is provided an electromagnetic relay in which a high sensitivity one-stable operation is easlly obtained by applying a simple operation.

Needless to say, two-stable type and center-stable type electromagnetic relays can be easily realized by the manner of bringing the adjusting springs into contact with the glass balls.

What is claimed is:

1. An electromagnetic relay comprising a header formed of a magnetic material and having magnetic pole pieces projecting with a spacing between them substantially in the middle part, a coil bobbin arranged on the above mentioned header and bearing an armature rotatably in a space within it, an exciting coil wound on the above mentioned coil bobbin, a yoke arranged around the upper part of the above mentioned coil bobbin, made of a magnetic material and opposed to the magnetic pole pieces projecting from the above mentioned header, a permanent magnet arranged between the above mentioned yoke and header, an operating spring interposed between the branched free ends of a driving piece fixed to each end of the above mentioned armature and operated by the driving piece to be opened and closed with a fixed contact, a fixing frame fixed in the bottom part of the above mentioned header and fixing the yoke, coil bobbin and permanent magnet and an adjusting spring extended from each side of the above mentioned fixing frame and having the free end arranged to press each driving piece.

2. An electromagnetic relay according to claim 1 wherein the distance for which one of the above mentioned adjusting springs moves while in contact with one driving piece and the distance for which the other adjusting spring moves while in contact with the other driving piece are made difierent from each other, the position in which the combined spring force by the spring force of the above mentioned operating spring and the spring force of the above mentioned adjusting spring becomes zero is displaced from the center of the travel of the above mentioned driving piece and the above mentioned combined spring force is so made as to be between the energizing attraction and opening attraction.

3. An electromagnetic relay according to claim 1 wherein the height of the permanent magnet arranged on the side of the coil bobbin and the height of the side of the coil bobbin are equal to each other and the side of the yoke is arranged on the side of the fixing frame.

4. An electromagnetic relay according to claim 1 wherein the operating spring is interposed between the two vertically branched tips of the driving piece fixed to each end of the armature rotating vertically to the header.

5. An electromagnetic relay according to claim 4 wherein a glass ball is fixed to each branched tip of the driving piece.

6. An electromagnetic relay according to claim 4 wherein a plurality of glass balls are fixed to the two branched tips of the driving piece so as to operate a plurality of operating springs.

7. An electromagnetic relay according to claim 1 wherein a permanent magnet holding part is formed near the branching point of the adjusting spring of the above mentioned fixing frame. 

1. An electromagnetic relay comprising a header formed of a magnetic material and having magnetic pole pieces projecting with a spacing between them substantially in the middle part, a coil bobbin arranged on the above mentioned header and bearing an armature rotatably in a space within it, an exciting coil wound on the above mentioned coil bobbin, a yoke arranged around the upper part of the above mentioned coil bobbin, made of a magnetic material and opposed to the magnetic pole pieces projecting from the above mentioned header, a permanent magnet arranged between the above mentioned yoke and header, an operating spring interposed between the branched free ends of a driving piece fixed to each end of the above mentioned armature and operated by the driving piece to be opened and closed with a fixed contact, a fixing frame fixed in the bottom part of the above mentioned header and fixing the yoke, coil bobbin and permanent magnet and an adjusting spring extended from each side of the above mentioned fixing frame and having the free end arranged to press each driving piece.
 2. An electromagnetic relay according to claim 1 wherein the distance for which one of the above mentioned adjusting springs moves while in contact with one driving piece and the distance for which the other adjusting spring moves while in contact with the other driving piece are made different from each other, the position in which the combined spring force by the spring force of the above mentioned operating spring and the spring force of the above mentioned adjusting spring becomes zero is displaced from the center of the travel of the above mentioned driving piece and the above mentioned combined spring force is so made as to be between the energizing attraction and opening attraction.
 3. An electromagnetic relay according to claim 1 wherein the height of the permanent magnet arranged on the side of the coil bobbin and the height of the side of the coil bobbin are equal to each other and the side of the yoke is arranged on the side of the fixing frame.
 4. An electromagnetic relay according to claim 1 wherein the operating spring is interposed between the two vertically branched tips of the driving piece fixed to each end of the armature rotating vertically to the header.
 5. An electromagnetic relay according to claim 4 wherein a glass ball is fixed to each branched tip of the driving piece.
 6. An electromagnetic relay according to claim 4 wherein a plurality of glass balls are fixed to the two branched tips of the driving piece so as to operate a plurality of operating springs.
 7. An electromagnetic relay according to claim 1 wherein a permanent magnet holding part is formed near the branching point of the adjusting spring of the above mentioned fixing frame. 